Infusion pumps have been used to provide a fluid containing medicine to a patient in a controlled manner. The fluid may be supplied in a bag with tubing extending. The tubing is operated on by the pump to provide a specified flow rate. In designing the pump schemes have been implemented to prevent continued flow of the fluid when the pump is opened or when tubing is removed from the pump so that the patient does not experience unwanted fluid pressure or receive an unwanted quantity of the fluid. A better system for automatically controlling fluid flow in the tubing has been needed, and such a system is provided in this patent application.